Prostate cancer incidence among workers occupationally exposed to radiation at the Mayak production association

At the present time there are some published research studies of the impact of ionizing radiation exposure on prostate cancer incidence and mortality. However, available information is controversial. Therefore it is necessary to continue research in order to collect new data. The main aim of this work is to study prostate cancer incidence among males exposed to radiation from different sources during their work at the Mayak Production Association (PA Mayak). The formed cohort consists of 16685 males employed at the Association from 1948 to 1982. For the period from1948 to 31.12.2013 183 prostate cancer cases were registered in the cohort, however we consider 166 cases of primary prostate cancer. In 152 of 166 cases the diagnosis was confirmed morphologically, in 14 cases the diagnosis was based on the set of diagnostic criteria typical for prostate cancer. This study used the following rates: age-specific prostate cancer incidence rate, standardized prostate cancer incidence, standardized incidence ratio. Expected number of cases was estimated on the basis of age rates of the national statistics of the Russian Federation for the adult population (older than 20 years). Incidence rates and standardized incidence ratios were estimated for 3 periods of follow-up (1948-1992, 1993-2002, 2003-2013). We found that prostate cancer incidence among PA Mayak workers increased by 1.7-1.9 times as compared with the rates of the national statistics of the Russian Federation. Prostate cancer in males worked in reactor and radiochemical production facilities, manifested at the younger age as compared with the national statistics, this fact may be connected with the professional work and occupational exposure to ionizing radiation.